View Compilation Error

0_0_17840929_26077.cpp: In function 'int topk(int*, int, int)':
0_0_17840929_26077.cpp:66:43: error: 'malloc' was not declared in this scope
  int *top = (int *) malloc(sizeof(int) * k);
                                           ^
0_0_17840929_26077.cpp:88:10: error: 'free' was not declared in this scope
  free(top);
          ^
0_0_17840929_26077.cpp: In function 'int main()':
0_0_17840929_26077.cpp:102:46: error: 'malloc' was not declared in this scope
    int *d = (int*) malloc(sizeof(int) * (n-1));
                                              ^
0_0_17840929_26077.cpp:122:10: error: 'free' was not declared in this scope
    free(d);
          ^